In haplodiploid species, an individual’s sex is determined not by the presence or absence of a sex chromosome, but instead by the number of copies of the genome in an individual’s cells.

Thrips are small haplodiploid insects in the order Thysanoptera (Crespi et al. 1992). Of about 5,000 species, about 300 form nests in plants called galls, feeding on plant tissue within.

The relatively short generation time and haplodiploid sex determination also contribute to the pest status of this species. These life history traits interact in complex ways to make western flower ...